1. Field of the Invention
The present invention relates to a developing roller that is incorporated into a developing device for use in an image-forming apparatus so as to transport and supply toner to an opposing area to a photosensitive member (a developing area), and more particularly, concerns a mono-component-developing-use developing roller.
2. Description of the Related Art
The mono-component-developing-use elastic developing roller, which is a developing roller to be incorporated into a developing device of a mono-component developing system, charges toner in a gap between it and a toner-regulating blade, and transports and supplies the charged toner to a developing area while supporting the charged toner.
Conventionally, with respect to the mono-component-developing-use elastic developing roller, those having a silicone-based elastic layer and a surface-coating layer formed on a substrate have been well known, from the viewpoint of charge-applying capability to toner and durability.
However, when the above-mentioned developing roller is used for a long time, problems are raised in that the toner charging property is lowered, in that the toner transport quantity to a developing area between the developing roller and the photosensitive member fluctuates and in that toner is fixed on the toner regulating blade. The toner fixing to the blade is conspicuous in the low-temperature, low-humidity environment. The degradation in the charging stability is conspicuous in the standard environment as well as in the high-temperature, high-humidity environment.